Automatic fuel-stoking apparatus



Patented May 17, 1921.

z SHEETS`SHEET I c. D. STEWART. AUTOMATIC FUEL STOKING APPARATUS.

APPLICATION FILED FEB. I0, 1920.

Q... .bw I N` f wm, v mn L 1 L M T .v A, m, 0.? In.. L mv, L w mv Ww mw m; INVENTOR CARLTON `D STEWART ATTORNEY v C. D. STEWART. AUTOMATIC FUEL sToKTNG APPARATUS.

APPLICATION FILED FEB.V I0, |920.

Patented May 17,

INVENTOR CARLTON ST EWART BYA AT1-'on NEY UNITED STATES PATENT OFFICE.

CARLTON D. STEWART, OF BERKELEY, CALIFORNIA, ASSIGNOR TO ASSOCIATED ENGI- NEERING AND SUPPLY COMPANY, OF SAN FRANCISCO, CALIFORNIA, A CORPORA- TION OF CALIFORNIA.

AUTOMATIC FUEL-STOKING APPARATUS.

Application filed February 10, 1920.

T 0 all whom t my concern Be it known that I, CARLTON D. STnwAR'r, a citizen of the United States, residing at Berkeley, in the county of Alameda and' State of California, have invented new and useful Improvements in Automatic lFuel- Stoking Apparatus, of which the following is a specification.

This invention relates to liquid and gaseous fuel burning apparatus, and more particularly to an automatic control mechanism therefor.

In certain forms of liquid fuel burning apparatus, instead of employing air or steam for atomization, the liquid fuelv is atomized by forcing the liquid out through a very small orifice under a very high pressure and temperature.

With the above type of apparatus, it is considered necessary to operate the fuel oilcontrolling valves so that they are either wide open or fully closed.

In view of the above, in order to secure automatic regulation of the fire in accordance with variations in steam boiler pressure, one object of my invention contemplates providing a plurality of burners and automatic controlling mechanism for shutting off certain burners at different. stages as the steam pressure in the boiler rises and for opening them up at corresponding stages as the steam pressure in the boiler falls, the mechanism being also adapted to regulate the draft to correspond with the number of burners in operation.

Other objects and advantages will appear in the following more detailed description of the invention.

.In the accompanying drawings; Figure l is a diagrammatic view of an automatic controlling mechanism for liquid fuel burning apparatus adapted for application to a steam boiler and embodying my invention; Fig. 2 an enlarged central sectional view of the master controller; Fig. 3 an enlarged central sectional view of the liquid fuel and damper regulator; and Fig. 4 a partial end elevation of the construction shown in Fig. 1, sufficient to show the relative arrangement of the operating arms which control the fuel burners and the dampers.

As shown in the drawings, the construction may comprise a master controller hav- Specification of Letters Patent.

Patented May 17, 1921.

serial No. 357,631.

ing controlling units 1 and 2 and a fuel valve and damper regulator comprising two similar regulating units 3 and 4.

Two or more pairs of fuel burners are provided, corresponding with the number of steps into which the regulation is to be divided and as is usual with the jet type of liquid fuel burner, each burner is surrounded by a rotatable draft door Each draft door 5 is provided with an arm 6, operatively connected to a rod 7 by means of a pin 8, which is carried by the rod and works in a slot 9 in the arm 6. The rods 7 are each pivotally connected to an arm 10 which is secured to an operating Shaft l1.

Liquid fuel is supplied to the burner. which is located at the center of cach t raft door 5, through a pipe 12 having a valve 13 for each burner and each valve is provided with an arm 14 operatively connecte-il to a. rod 15. The rod 15 is pivotally connected to an arm 16 secured to the shaft 11.

A stack damper 17 is also operatively connect-edto the shaft 1l through an arm 18, rod 19, and an arm 20, the stack damper being provided with a weighted arm 21 tending to move the damper to its open position.

A manually controlled pilot burner is also provided, having a draft door 5 surrounding the burner, and a manually operated valve 22 for controlling the supply of liquid fuel from the supply pipe 12 to the burner.

The master controller and the fuel valve and damper regulator are of a construction somewhat similar to the construction shown in. prior Patent No. 1,314,174 of S. S. lVecks and C. D. Stewart, dated August 2G, 1919.

Each of the units 1 and 2 of the master controller may comprise a casing containing a diaphragm 23, subject on one side to the pressure of steam in the steam boiler as supplied through pipe A24 and on the opposite side to the pressure of a coil spring 25.

The diaphragm 23 is provided with a stem 26 for operating a valve 27. The casing also contains a differential piston comprising piston heads 28 and 29 connected by a stem 30 and the valve 27 controls the exhaust of liquid under pressure from pis-ton chamber 31, through a passage 32 to an exhaust or return pipe 33,

The chamber 34 intermediate the piston heads 28 and 29 of the unit l is connected to a pipe 35, leading to` the regulator unit 3 and chamber 34 of the unit 2 is connected to a pipe 36 leading to the regulator unit 4.

The piston head 29 is provided with a valve 37 for controlling communication from the supply pipe 12 to the respective pipes 35 and 36.

Each unit of the fuel valve and damper regulator may comprise a casing having a piston chamber 38 containing a piston 39. Each piston is provided with a stem 40 and the stems are connected by a sprocket chain 41 which passes over a sprocket wheel 42,

l carriedby a rod 43. The rod 43 is pivotally connected to an arm 44 secured to the shaft 11.

The piston chamber at the under side of each piston 39 is connected to the exhaust or return pipe 33 and the piston chamber above each piston is connected to the respective pipes 35 and 36.

In operation, the springs 25 are adjusted to the desired steam pressure, for example, the spring 25 of the unit 1 may be adjusted to the maximum steam pressure which it is desired to carry in the steam boiler, while the spring 25 of the unit 2 may be adjusted to within one or two pounds of this maximum steam pressure.

Assuming that the fires are burning, if the steam pressure in the boiler has increased to a point slightly exceeding the pressure of the spring 25 of the unit 2, which is assumed to be less than the maximum steam pressure, the diaphragm 23 of unit 2, will move downwardl and open valve 27.

As in the hereinbe ore mentioned patent. liquid fuel under pressure is constantly supplied to the pipe 12 by the operation of a pump and thence flows through a passage 45 to piston chamber 31 of each unit 1 and 2, so that normally the differential piston is maintained in its lower position, seating the valve 37, by the pressure of liquid fuel in the piston chamber 31.

When the valve 27 is opened by the operation of diaphragm 23 of the unit 2, as above described, liquid fuel under pressure is exhausted from piston chamber 31 to the return pipe 33 faster than it can be supplied through the restricted passage 45, so that the pressure of liquid fuel which acts below the piston head 29 will be sutlicient to shift the differential piston to its upper position, as shownin Fig. 2 of the drawing.

Liquid fuel under pressure is then admitted from supply pipe 12 to the pipe 36 and flows thence to the piston chamber above the piston 39 of the unit 4 and thereby causes the downward movement of said piston. The downward movement of the pulley 42 and the rod 43 is thus caused and the shaft 11 is therefore partially rotated, so

as to partly close the stack damper 17 and at the same time, the rods 7 and 15 are operated so as to rotate the draft doors 5 and the valves 13.

The valves 13 are so positioned that when the above movement occurs, the upper pair of valves 13, as shown in Fig. 1 of the drawings, are moved to their fully closed positions, while the lower pair of valves 13 remain open.

The upper pair of draft doors 5 will be rotated so that the openings .46, for admitting air to the upper burners will be closed, while the openings 46 controlled by the lower pair of draft doors will remain open.

With the upper pair of burners cut off and the stack damper partly closed, the lire under the steam boiler will be reduced.

Should there be further increase in steam pressure in the boiler, sufficient to overcome the pressure of the spring 25 on the diaphragm 23 of the unit 1, the valve 27 of this unit will be opened to cause the operation of the differential piston, so that liquid fuel under pressure will be supplied to the pipe 35 and thence to the chamber above the piston 39 of the regulator unit 3.

A further downward movement of the pulley 42 vand the rod 43 is thus produced and the shaft 11 is further rotated, so as to close the lower pair of valves 13 and the lower pair of draft doors 5.

While this movement further rotates the upper pair of draft doors 5 and the valves 13, the arrangement is such that the valves and the doors still maintain their closed positions.

Therotation of the shaft 11, as above described, also causes a further closing movement of thestack damper 17, as will be evi.- dent.

It will now be seen that both the upperand the lower pairs of burners are fully closed and the fire under the boiler is only that (lue to the manually controlled pilot burner, which is controlled by the valve 22. If the boiler pressure should become reduced below the maximum pressure, the diaphragm 23 of the master controller unit 1 will be moved by the spring 25, so as to close the corresponding valve 27, thus permitting pressure of liquid fuel to build up in the piston chamber 31 by flow through the restricted passage 45.

The differential piston of the unit l will I then be movedA downwardly so as to close the valve 37 and the liquid fuel under pressure above piston 39 of the regulator unit 3 is exhausted through pipe 35,' by way of the intermediate chamber 34 and a passage 47, to the return pipe 33.

The shaft 11 is thenl partially rotated through the action of the weighted arm 48, causing the stack damper 17 to move to a more open position and opening the valves 13 and the draft doors 5 of the lower pair of burners so that the lire is increased by the addition of the lower pair of burners.

If the steam pressure should reduce still further, then the valve 27 of the unit 2 will be closed so that the correspondin differential piston will be operated to c ose the valve 37 and cut off the supply of liquid fuel to the piston 39 of the regulator unit 4.

Since the liquid pressure above piston 39 is relieved, the weighted arm 48 is free to rotate the shaft 11 to a further extent, so that the stack da/mper 17 is opened wider and the valves 13 and the draft doors 5 of the upper pair of burners are opened, thus increasing the re under the boiler by the addition of the upper pair of burners.

It will now be apparent that the above described apparatus operates to positively open u one or more burners and the correspon ing draft doors at each step as the steam pressure diminishes and to close 0H one or more burners and the corresponding draft doors step by step as the pressure in the boiler increases.

Any desired number of liquid fuel valve and damper regulators may be governed by the master controller and additional master controller units and fuel valve and damper regulators may be employed in order to provide an increased number of lsteps in the re ulation.

aving now described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a liquid fuel burning apparatus, the combination with a plurality of pipes for supplying liquid fnel to corresponding liquid fuel burners, of a valve for controlling the supply of liquid fuel to each pipe, a regulating mechanism' for operating said valves'and having different positions for fully opening or closing one or more of said valves, and a controlling device operated according to variations in steam pressure for effecting the operation of said mechanism.

2. In a liquid fuel burning apparatus, the combination with a plurality of pipes for supplying liquid fuel to corresponding liquid fuel burners, of a valve for controlling the supply of liquid fuel to each pipe a regulating mechanism for moving said v alves to the fully opened and closed positions and having one position in which all valves are closed, another position in which all valves are opened, and another position in which part of the valves are closed and part are opened, and a master controller governed by steam pressure for effecting the operation of said regulating mechanlsm. y

3. In a liquid fuel burnin apparatus,

the combination with a plura ity of plpes for supplying liquid fuel to corresponding liquid fuel burners and a draft door for regulating the draft for each burner, of a valve for controlling the supply of liquid fuel to each pipe, a regulating mechanism mechanically connected to said draft doors and said valves and having different operating positions for opening or closing one or more of said valves and the corresponding draft doors, and a master controller governed by variations in steam pressure for effecting the operation of said mechanism.

4.' In a liquid fuel burning apparatus, the combinatin with a plurality of pipes for supplying liquid vfuel to corresponding liquid fuel burners, of a valve for controlling the supply of liquid fuel to each pipe, a regulating mechanism for operating said valves and having different positions for opening or closin one or more of said valves, a controlllng device governed by variations in steam pressure for effecting the operation of said mechanism, a pipe for supplying liquid fuel to an additional burner,

and a manually controlled valve for regulating the supply of liquid fuel to said pipe.

5. n a liquid fuel burning apparatus, the combination with a plurality of pipes for supplying liquid fuel to corresponding liquid fuel burners, of a valve for controlling the supply of liquid fuel to each pipe, a draft door for regulating the draft for each burner, a rotatable shaft operativel connected to said valves and -said dradoors and having different positions in which one or more of said valves and draft doors are opened or closed, and a regulating mechanism for rotating said shaft.

In testimony whereof I have hereunto set m hand.

y CARLTON D. STEWART. 

